The present disclosure relates to diverting agents and associated methods of use in subterranean treatments.
Diverting agents may be used in a variety of subterranean treatments. Such treatments include, but are not limited to, drilling, stimulation treatments (e.g., fracturing treatments, matrix acidizing treatments), and cementing operations. For example, after a well bore is drilled and completed in a subterranean producing zone, it is often necessary to introduce a treatment fluid into the zone. For example, a producing zone can be stimulated by introducing an aqueous acid solution into the matrix of a producing zone to dissolve formation material or materials near the wellbore which impede well productivity, and thereby increase its porosity and permeability. This results in an increase in the production of hydrocarbons therefrom. To insure that the producing zone is contacted by the treating fluid uniformly, a particulate solid diverting agent may be placed in the zone to direct the placement of a desired treatment fluid. One technique has been to pack the diverting agent in perforation tunnels extending from the well bore into the subterranean zone. The diverting agent in the perforation tunnels causes the treating fluid introduced therein to be uniformly distributed between all of the perforations whereby the subterranean zone is uniformly treated. The term “zone,” as used herein, simply refers to a portion of the formation and does not imply a particular geological strata or composition.
Traditional diverting agents may be grouped into two classifications. Such classifications include viscous fluid diverting agents and physical/mechanical diverting agents. In the former, typically, a relatively high viscosity fluid flows into a subterranean zone, creating a resistance that causes subsequent treatment fluids to be diverted to other portions of the formation. Such diversion methods are considered relatively easy to implement, but are generally thought not to be as effective as diverting agents that introduce a physical or mechanical barrier. Additionally, high temperatures associated with wells of greater depth lead to increased instability of such viscosified fluids.
In some cases, conventional diverting agents may not completely block off or divert the fracturing fluid, which results in fluid loss or leak-off into the formation, especially at the first few seconds after the fluid is injected into the zone. This initial phase of high fluid loss is known as a “spurt.” The spurt typically ends within a few seconds; however fluid loss in typically persists.
While embodiments of this disclosure have been depicted and described and are defined by reference to example embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.